as in treacherous
formal
causing harm in a way that is gradual or not easily noticed
Most people with this insidious disease have no idea that they are infected. an insidious enemy
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Example Sentences
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Recent Examples of insidious
Stunning advances in genetic science have revealed the subtle, insidious culprits behind these brutal diseases and have started paving the way for treatments.
—
Laura Ungar, Los Angeles Times, 30 Apr. 2025
How To Get Rid Of Spider Mites These insidious pests can kill a plant (and spread to other plants) if left unchecked, so try these management tips from Bertone and Khan:
Inspect your plants.
—Arricca Elin Sansone, Southern Living, 30 Apr. 2025
The Overconfidence Illusion Overconfidence is arguably the most insidious of leadership biases.
—Paola Cecchi-Dimeglio, Forbes.com, 16 Apr. 2025
If the other AGIs take the bait, the insidious AGI stands tall as the best, assuming nobody finds out the underhanded gambit at play.
—Lance Eliot, Forbes, 21 Mar. 2025
See All Example Sentences for insidious
Laura Ungar, Los Angeles Times, 30 Apr. 2025
How To Get Rid Of Spider Mites These insidious pests can kill a plant (and spread to other plants) if left unchecked, so try these management tips from Bertone and Khan:
Inspect your plants.
—Arricca Elin Sansone, Southern Living, 30 Apr. 2025
The Overconfidence Illusion Overconfidence is arguably the most insidious of leadership biases.
—Paola Cecchi-Dimeglio, Forbes.com, 16 Apr. 2025
If the other AGIs take the bait, the insidious AGI stands tall as the best, assuming nobody finds out the underhanded gambit at play.
—Lance Eliot, Forbes, 21 Mar. 2025
See All Example Sentences for insidious
Recent Examples of Synonyms for insidious
Adjective
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The pine trees are towering and the fairways are twisting and the bunkers are deep and treacherous.—
Alex Zietlow,
Charlotte Observer,
15 May 2025
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Maybe the seemingly long haul on I-95 made treacherous by traffic congestion creates the Miami-Dade County and Broward County division among its residents.—
Michelle F. Solomon,
Miami Herald,
13 May 2025
Adjective
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With its strapless neckline, subtle side slit, and body-hugging silhouette, it was made for sipping cocktails under palm trees in Miami or dancing the night away in Barcelona.—
Rosie Marder,
Travel + Leisure,
13 May 2025
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Vasudevan explains that cats use their paws not just for hunting or defending, but also for play and subtle communication.—
Maria Azzurra Volpe,
MSNBC Newsweek,
13 May 2025
Adjective
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Now their weird discomfort with disease—and their outré views on cancer in particular—is being refracted through a sea of false, indecent speculations.—
Benjamin Mazer,
The Atlantic,
19 May 2025
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This discrepancy hindered the adoption of BI, which might further damage AI by generating models that are trained with false assumptions and generate erroneous predictions.—
Artyom Keydunov,
Forbes.com,
19 May 2025
Adjective
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In the 1970s, information about the Tuskegee study – a deceptive and unethical 40-year study of untreated syphilis in Black men – came to light.—
Christine Coughlin,
The Conversation,
9 May 2025
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Anyone wanting to fight such usage would have to rely on deceptive practice laws, trademark and copyright protection, and state-specific laws protecting a person's name, image, and likeness.—
Neil J. Rubenking,
PC Magazine,
2 May 2025
Adjective
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Jake Gyllenhaal is his foil as the perfidious Iago, who goads Othello into unreasoning jealousy with lies about his beloved Desdemona (Molly Osborne).—
New York Times,
New York Times,
17 Feb. 2025
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Since then, Putin has sought instead to rally the public to the defense of a motherland besieged by the perfidious and cunning West.—
Leon Aron,
The Atlantic,
5 Dec. 2024
Adjective
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Common factors that contribute to misconfigurations include: • Human Error: Typing mistakes, syntax errors or incorrect command sequences.—
Alexander Britkin,
Forbes.com,
9 May 2025
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That is the correct decision for her and her game, but also the incorrect decision for all of us at home watching a television program.—
Brian Moylan,
Vulture,
8 May 2025
Adjective
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Ship was heading the wrong direction The training ship arrived at New York's Pier 17 and was open to the public to visit from May 13 to 17, according to the Mexican Consulate in New York.—
N'dea Yancey-Bragg,
USA Today,
19 May 2025
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The Final Destination: The NASCAR incident The opening disaster of The Final Destination is a NASCAR race gone horribly wrong.—
Keith Langston,
People.com,
18 May 2025
Cite this Entry
“Insidious.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/insidious. Accessed 23 May. 2025.
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